Shaving device



July 14, 1942. x A. P. MILLER 2,289,447

SHAVING DEVICE Filed Aug. 5, 1958 Patented July 14, 1942 UNITED o STATESPATENT GFFICE -sHAvmG DEVICE Anthony r. Miner, Atlantic City, N. J.Application August s', 193s, serial No. 223,152

3 Claims.

This invention relates to a shaving device, and more particularly to aso-called electric shaver in which a driving motor for a cutterrislocated within a housing adapted to be grasped in the hand of the user.

Shaving devices of the general character just indicated have beenprovided with reciprocating cutters which must of necessity be drivenfrom a rotary motor through some means capable of transforming therotary motion of the motor shaft into the reciprocatory m'otion of thecutter. inasmuch as a shaving device of this type must of necessity besmall and have a motor incapable of supplying any large amount ofdriving power, and inasmuch as such a device is subject to considerableabuse through nonfoiling and the accumulation of dirt, primarily theclippings o f hair, it is obvious that any additional elements in themechanism only serve `to increase the tendency toward failure ofoperation. A considerable load is, furthermore, imposed in reciprocatorydevices due to several causes. First; the

vrelatively movable and stationary-blades must y be in contact toprovide proper cutting and, in

general, the arrangements have been such that all of the pairs ofcutting elements produce their cuts simultaneously. Thus in operationsudden loadsare placed on the reciprocating mechanism which, inconjunction with friction, tend to-pre .vent its proper operation. Inreciprocatingv devices, furthermore, dirt entering between therelatively moving cutting elements tends to remain there since there isno cleaning sweep serving to dislodge it, with the result that it maynot be dislodged for considerable periods during which friction isgreatly increased. It is difiicult, furthermore, to provide relativelyreciproeating surfaces which remain in sufficiently close lcontact toprovide an effective shearing action.

' In accordance with the present invention, there is provided a shavingdevice in which the moving Accumulation of dirt is effectively avoidedby reason ofthe continuous rotation of the cutter whereby it tends toclean thevcooperating cutter surfaces. The rotary action furtherfacilitates shaving when perspiration isoccurring since the 'apidlyrotating screw tends to keep the face dry aidcool.

I have discovered, furthermore, that greatly improved operation may beprovided if the cutting surfaces, which arenecessarily of hardenedsteel, do not in themselvesprovide the bearing for a cutter. Inaccordance with the preferred embodiment of the present invention, therotary cutter is provided with bearing elements of suitable bearingmetal which, under the urging of a spring, serve to maintain the cuttingsurfaces in proper contact without producing any binding.' The above andother objects of the invention, primarily relating to details ofconstruction, will be apparent from the following description, read inconjunction with the accompanying drawing, in which:

Figure 1 is a plan view partially broken away illustrating a preferredembodiment-of the inventidn;

Figure l2 is a lengthwise section through the cutting elements thereof;

' Figure 3 is an end view of the cutting elements;

Figure 4 is a transverse section taken on the plane the trace of whichis indicated at d-ll in plane the trace of which is indicated at t-- inFigure 2; and

Figure 6 is a perspective sectional view showing a modified arrangementof cutter.

Referring first to Figures i to 5, inclusive, the improved shavingdevice comprises a housing 2 which may be of plastic material andwhichis exteriorly shaped to be gripped by the hand of a user of thedevice. A driving electric motor 4,

preferably of the universal type commonly used in shaving devices ofthis nature is enclosedwithin the housing 2 with its shaft 6 extendinglengthwise of the housing. Alternatively, a a spring motor may be used,or the cutter may be driven from a remote motor through a flexibleshaft. Secured to one end of the housing, and preferably covered byportions thereof,

broken away in Figure l, is a supporting frame 5 thin wall adjacent theslotsl is cylindrically formed, as indicated at 24, to closely embraceal which Amay be brazed or otherwise secured in A place and which leavesopenings 30 fo'r the exit of cuttings accumulating within the memberI4..

Within the slots I8 and IB-there is located a transverse bearing member32, preferably formed of some material such as bronze or the like, whichwill provide with a hardened` steel shaft a proper bearing. A similarbearing 34 extends through the slots 29 inwardly of the closure element28. Mounted in thosebearing members -32 and 34 Ais a hardened screw II,the shaft 38 of which extends inwardly to engage the shaft B of themotor. The screw cutter 36 thus provided is urged into engagement withthe cylindrical portion 24 of the thin wall carrying lthe slots vbymeans of a spring 40 held to the tubular member I4 by screws 42 andyieldingly urging the bearing members 32 and 34 in a .direction to causethe screw to bear upon the thin wall adjacent thel slots. The screw 38is provided with one or more threads providing cutting edges designed tocooperate with lthe edges of the slots 22 for shearing purposes and alsoproviding conveying means for moving cuttings lengthwise of the barrelto the discharge. The thread or threads of the screw 36 may be square incross-section or slightly. hollow ground at their edges to provide for abetter cutting action. The outside diameter of the threads is made suchas to provide a good fit with a cylindrical surface 24. The slots mayextend directly across the axis of the screw,

but preferably the slots are so arranged as to` extend in the directionof the helix angle of th screw' at itsA periphery. Under suchcircumstances there is a greater opportunity for the entra'nce kQf hairinto the slots, particularly if the screw. has alarge pitch, andconsequently more rapid cutting action. This is in contrast to-thelittle opportunity afforded for entrance of hairsv in the usualreciprooatory cutter. vThe slots 22 are preferably as narrow as they maybe consistent with the.proper entrance of hair, and

should be sufficiently long to receive long hairs as well as shortstubble.

While it is possible to have a cutter screw of l ment being such thatthecutting edge of said the type described located within the cuttercylinder fitting it relatively tightly'and provided with the cuttingslots, and therefore hardened, I have found that such an arrangement ismore likely to produce overheating and cause the accumulation of dirtand impede action than an arrangement such as that described in whichthe contact of the hardened steel parts is limited to the portionsnecessary for cutting purposes. This willl be evident from Figure 4, inwhich it will be noted that the contact occurs substantially only overthat area which is slotted. With such an arrangement, the bearing forthe rotating screw -may be made of proper bearing material such asbronze and, furthermore, the dirt is swept from between the cuttingsurfaces into the open portion 2i of the tubular member wherein it mayaccumulate and ultimately fall out through the openings 30. A springsuch as 40 may be readily adjusted to secure the proper bearing tensionbetween the cutting surfaces.

v'Ihe operation of the device just described is substantially superiorto that of reciprocating devices heretofore known. Though the cutter is4 cutter.

nght m weight. its weight is to some extnt com. parable with the weightof the rotating parts of the motor, and consequently it contributes tomaintaining the speed of the motor substantially constant' so as toovercome the irregular loads imposed by the cutting. Without a rotaryaction there can, of course be no such effect, and the tendency ofreciprocating devices is to stop under conditions of maximum load. Aself-cleaning actionalso results from the use of the rotary drical wallsmay be adiusted so as to properly maintain the running clearances insuch condition as to provide proper cutting. The bore 40 permits theescapeof cuttings. The device of this figure may .be used eitherwithoutonwith separate bearings of the type described in connection withthe previous modification. Instead of having a bore 46, the block may beopen on the upper slide of the bore 4`I, i. e., of U-shaped form.

.What I claim and desire to protect by Letters Patent is:

1. A shaving device comprising a member having a thin wall provided withslots for the entrance of hairs, a screw engaging said thin Wall withits axis extending transversely of said slots, said screw having athread provided with a cutting edge forming a shearing arrangementinconjunction with edges of the slots, each slot having at least one edgearranged for shearingl cooperation with said cutting edge of the screwand extending in the direction of the threads at an' angle to thedirection/of the screw axis substantially corresponding to the helixangle of the screw, and each slot extending through a substantialcircumferential extent of said thin wall, and means for rotating saidscrew, said arrangethread meets vall parts of the cooperating edge of aslot substantially simultaneously during rotation of the screw.

2. A shaving device comprising a member having a thin wall provided withslots for the entrance of hairs, a screw engaging said thin wall withits axis extending transversely of said slots,

said screw having a thread provided with va cuthave extended engagementwith, said screw, y

means for yieldingly urging said screw into continuous engagement withthe cylindrical surface of said thinwall, and means for rotating saidscrew, said arrangement being such that the cutting edge of said threadmeets all parts of the assaut' cooperating edge of a slot substantiallysimultaneously during rotation of the screw.

3. A'shaving device comprising a memberhav'- ing a thin wall providedwith slots for the entrance of hairs, a screw engaging said-thin wallwith its axis extending transversely of said slots,

s'aid screw having a thread provided with a cutting edge forming ashearing arrangement in conjunction with edges oi the slots, each slothaving at least one edge arranged tor shearing cooperation with saidcutting edge oi the screw and extending inthe direction of the threadsat an angle to the direction ot the screw axis suby 3 stantialiycorresponding to the helix angle of the screw, 'and each slot extending.through a substantiai circumferential extent of said thin wall,

ousiy during rotation bearings for said screw movable independently ofeach other relatively t'osaid thin wall, resilient means acting uponsaid bearings to urge said screw yieldingly into continuous engagementwith said thin wall,l and means for rotating said screw, saidarrangement being such that the cutting edge of said thread meets-allparts of the coa operating edge of a slot substantially simultaneof thescrew.

ANTHONY P. MILLER.

